Martin Richards developed a high-level computer language called BCPL in the year 1967. The intention was to develop a language for writing an operating system (OS). As you know an OS is software which controls the various processes in a computer system. This language was later improved by Ken Thompson and he gave it a new name B. The basic ideas about some topics such as arrays, etc., which were later inherited by C were developed in BCPL and B. In those days, the development of computers was in infancy. One of the serious constraints experienced while developing the language B was the small computer memory available at that time.

when we said that every language consists of keywords and that these keywords are only understandable by the people who speak the language.The same is with C; keywords are special words that have special meaning in the C language and are reserved by the language. That last sentence has significant meaning, so I will take about it a little later on.

There are many "languages" like, for example C, Fortran, PASCAL etc., that help us to convert an algorithm in to something that a computer can understand. We will focus here only on C programming So. let us start looking at how do we create a "C program".

The main role of header file is it is used to share information among various files.To put it brief, if we have several functions say 4 functions named as f1, f2, f3, f4 placed in file say sample.c and if all the functions want to get accessed each other all must be placed in the same file sample.c.

We can read a string using the %s conversion specification in the scanf function. However, it has a limitation that the strings entered cannot contain spaces and tabs. To overcome this problem, the C standard library provides the gets function. It allows us to read a line of characters (including spaces and tabs) until the newline character is entered, i. e., the Enter key is pressed. A call to this function takes the following form:

We have some compiler preprocessor commands. This includes various #include files. Then comes the main function. Some name can also be given to the main function. Then, we have the variable declarations used in the main code. Then we have sub-functions.

Another component common to C programs is the header file. This supplies information about the standard library functions. These files all end with the .h extension and are added to the program using the #include pre-processor directive. All C compilers use a pre-processor as their first phase of compilation to manipulate the code of the source file before it is compiled.

Escape sequences are basically control characters used for formatting the output. These are combinations of a backslash and a character in lowercase. We have already used "\n", which shifts the curser to the next line. Table lists the escape sequences defined in C language.

The standard C library provides several functions and macros for character 1/0. Here we consider the getchar and putchar macros. As these macros read or write a single character, they are typically used in a loop to read/write a sequence of characters.

BASIC stands for beginner's all-purpose symbolic instruction code, and is a computerprogramming language that was invented in 1964 at Dartmouth University by John G Kemeny and Thomas E Kurtz. BASIC has the advantage of English-like commands that are easier to understand and remember than those of most other languages. Even so, the latest versions of BASIC can do just about anything programming languages like C or Pascal can do.